Blade of Blood and Bone

When you cast this spell, you cut your body with the material component, your hit point maximum decreases by 3 and the material component disappears. For the duration, you can use a bonus action to draw a blade made of your own bone, blood, and sinew from your body. The blade is a magical weapon, uses your spell attack bonus when you attack with it, and deals 1d6 slashing damage on a hit. You are considered proficient with the blade. As a bonus action, you can slide the blade back into your body to conceal it. When the duration ends, the incision in your body disappears, your hit point maximum is restored, and the material component reappears.

 At higher Levels: When you cast this spell using a spell slot of 2nd level or higher, the damage dealt by the blade increases by 1d6 for every 2 slot levels above 2nd, and your hit point maximum decreases by an additional amount equal to the level of the slot used.